Landing light swiches off all downstairs lights

[VeryBaffled]

Yes, definitely two circuits. House built early 1980s and has fuse box of that era with fuse wire.
I might be confusing you with the gang terminology as I tend to equate the number of gangs to the number of individual switches on the switch which I know is wrong.
So as far as I know there are no links but it does all point towards this so maybe I'm wrong.
I can't take a picture just now but will try later. I don't think it is the upstairs one as we haven't touched this for 4plus years. At that time I replaced a single plastic white switch with a metal one. All seemed fine. This just links to the downstairs switch in that I can switch the landing light on from top or bottom.
Thanks for your patience.

 

[sparkwright]

Have you done anything to the light fittings recently?

Wouldn't expect any links now you have confirmed it's two seperate circuits.

Are the red, yellow and blue wires at the 3 gang switch all from the same CABLE?

 

[AndyPRK]

My bet / thoughts

The red wires and on the left and middle have been mixed up.

The ground floor light circuit is open circuit (or MCB tripped) and is being powered from the landing light somehow.

I know this doesn't explain it all.

Need a picture of the backbox of the 3 gang

 

[VeryBaffled]

Thanks everyone. Will wait till daylight to do photos but in the meantime can confirm that the cables going in are not all together. red and black from one cable, yellow is on its own.

 

[sparkwright]

Thanks everyone. Will wait till daylight to do photos but in the meantime can confirm that the cables going in are not all together. red and black from one cable, yellow is on its own.

The red, yellow and blue for the landing switch at the 3 gang switch should all come from ONE CABLE.

If you've mixed this up somehow then the up and down circuits will be crossed, and would explain the behaviour you are experiencing.

A better picture of the 3 gang switch will help.

 

[VeryBaffled]

Sounds like we might be making progress in finding the problem - not sure when I will be able to get the photo to you as out in the morning but will post back on here as soon as
I can. Thanks everyone, so glad I found this site.

 

[JohnW2]

T... in the meantime can confirm that the cables going in are not all together. red and black from one cable, yellow is on its own.

Unless something very odd is going on, the yellow and blue connected to the nearest switch in your first picture must be coming from the same cable, and the only question is whether the red going to that switch also comes from that same cable (as the blue and yellow) - which it almost certainly should do.

Kind Regards, John

 

[JohnW2]

The red, yellow and blue for the landing switch at the 3 gang switch should all come from ONE CABLE. ... If you've mixed this up somehow then the up and down circuits will be crossed, and would explain the behaviour you are experiencing.

You may be right (about it explaining the observed behaviour) but I'd have to think (and probably scribble) fairly deeply to work out how that could result in all the downstairs lights not working with that landing switch in one position (if I'm understanding correctly that to be the case).

Kind Regards, John

 

[ericmark]

It would seem the red yellow and blue coming from same cable is the route of the problem. I have not worked out the scenarios I can't see how swapping reds would cause the reported events but it does seem the most likely.

 

[sparkwright]

The red, yellow and blue for the landing switch at the 3 gang switch should all come from ONE CABLE. ... If you've mixed this up somehow then the up and down circuits will be crossed, and would explain the behaviour you are experiencing.

You may be right (about it explaining the observed behaviour) but I'd have to think (and probably scribble) fairly deeply to work out how that could result in all the downstairs lights not working with that landing switch in one position (if I'm understanding correctly that to be the case).

Kind Regards, John

Like Eric, I certainly haven't bothered to think how this may be possible - if indeed it even is.

Easier to wait for the more detailed pictures.

 

[ban-all-sheds]

Easier to wait for the more detailed pictures.

And better, by a country mile, to go for Plan A or Plan B, not Plan C.